生理学报Acta Physiologica Sinica, June 25 2003 55(3)
研究论文
组织学与核磁共振检测大鼠癫痫源性早期脑损伤的跨半球扩布特征
韩丹1,*, 臧颖1, 杨运煌2, 刘买利2, 王文挺1, 邹祖玉3
1武汉大学医学院生理学系、 2中国科学院武汉物理与数学研究所波谱与原子分子物理国家重点实验室; 3武汉大学医学院病理学与病理生理学系, 武汉 430071
摘要: 慢性强直电刺激(60 Hz, 2 s)大鼠右侧背海马(hippocampus, DHPC)CA1基树突区, 1次/d, 连续刺激10 d。分别在施加强直电刺激的第2、 4、 6、 8或10 d时进行核磁共振成像检测(T2 weighted magnetic resonance image, T2-WI), 并对鼠脑进行组织学切片鉴定。结果表明, 早期慢性癫痫源性脑损伤的病理性形态特征主要包括: (1) T2-WI检测侧脑室(lateral ventricle, LV)区域信号增强、 组织学检测LV扩大和双侧对称性脉络膜丛病理性增生, 后二者并非完全平行呈现。(2)组织学切片显示双侧LV扩大面积与T2-WI信号增强区域面积的脑区分布近似。与空白对照组大鼠相比, 电刺激2、 4、 6、 8和10 d后, T2-WI信号增强区域面积显著增大(P=0.0259; P=0.0184; P=0.0184; P=0.0404; P=0.0259)以及组织学鉴定LV面积增大(P=0.0210; P=0.01; P=0.0100; P=0.0152)。(3)定侧分析显示, T2-WI信号增强区域、 T2-WI信号增强区域面积和组织学鉴定LV扩大面积, 在慢性刺激6 d时均以植入电极的对侧为主; 第 10 d时均以同侧为主。 三项观察结果的一致性证实了癫痫源性早期脑损伤的跨半球动态扩布特征。
关键词: T2加权核磁共振; 侧脑室扩大; 癫痫; 大鼠
中图分类号: Q424; R742.1
The propagation
of brain injuries from artificial focus into the opposite hemisphere at the
early stage of electrogenic rat epilepsy identified by histology method and
magnetic resonance image
HAN Dan1,*， ZANG Ying1, YANG Yun-Huang2, LIU Mai-Li2, WANG Wen-Ting1, ZOU Zu-Yu3
Departments of 1Physiology, 3Pathology and Pathophysiology, Medical College, Wuhan University, Wuhan 430071;
2Laboratory of Magnetic Resonance Atomic and Molecular Physics, Wuhan Institute of Physics and
Mathematics, Chinese Academy of Sciences, Wuhan 430071
Abstract:The popurse of this work was to study the characteristics of rat brain abnormalities across two hemispheres at the early stage of electrogenic epilepsy. Experiments were performed on 37 male Sprague-Dawley rats. Chronically repetitive tetanization (60 Hz, 2 s, 0.4－0.6 mA) was used to stimulate the right dorsal hippocampus (DHPC) of the rat brain once a day for 2, 4, 6, 8 or 10 d, respectively. The T2-weighted (T2-WI) spin-echo images were obtained from each experimental rat at the end of the experiments. Histological sections were obtained after experiments were finished. The results showed that the main pathologic changes at the early stage of epilepsy included: (1) T2-WI hyperintensity, the histologically enlarged lateral ventricle (LV) and pathological hyperplasia of ventricular choroidea plexus which was symmetric in two hemispheres but not in parallel to the LV enlargement; (2) histologically enlarged LV area showed a resemblance to T2-WI hyperintensive area. Compared with the control rats, appeared large T2-WI hyperintensive area (P=0.0259; P=0.0184; P=0.0184; P=0.0404; P=0.0259) and histologically enlarged LV area (P=0.0210; P=0.01; P=0.0100; P=0.0152) were presented in chronically tetanized rats; and (3) dynamic characteristics of histologically enlarged LV area resembled to those of T2-WI hyperintensity area in chronically tetanized rats at different stimulating day. Lateralization of T2-WI hyperintensity was in accordance with that of T2-WI abnormali area and of histologically enlarged LV: there were worse contralateral side to the electrode implanted on the stimulating d 6 and worse ipsilateral side to the electrode implanted on the stimulating day 10. These results imply characteristic propagation of brain abnormalities crossing to the opposite hemisphere at the early stage of an electrogenic rat epilepsy.
Key words: brain; magnetic resonance imaging; lateral ventricle; epilepsy; rats